39. Generally speaking, if 　　　　　　according to the instructions, the electric-bike is not dangerous as reported.

　 A. riding　　　　 B. ridden　　　　 C. to ride　　　　 D. to be ridden

38. The factory has produced 　　　　　　　it did last year.

　 A. twice more cars as　　　　 B. twice as many cars as

　 C. twice as much cars as　　　 D. as twice many cars as

37. It was in America, therefore, 　　　　　　　the great advances in nineteenth-century agricultural machinery first came.

　 A. where　　　　　 B. when　　　　　 C. that　　　　　　 D. in which

36. Time spent on a beautiful beach can be very enjoyable 　　　　　　　you go for a holiday for a visit to your friends.

　 A. if　　　　 B. when　　　　 C. no matter　　　　 D. whether

35. It is interesting to observe 　　　　　　　common words have found their way into the language from the names of people.

　 A. how much　　　　 B. how soon　　　 C. how many　　　　 D. how long

34. Any habit 　　　　　　slows down your silent reading to the speed at which you speak, or read aloud, is inefficient.

　 A. which　 　　　B. that　　　　 C. /　　　　　 D. who

33. The amount of rain and snow falls 　　　　　　　a great difference to the climate.

　 A. make　　　 B. and making　　　　 C. to make　　　　 D. makes

32. It was announced that only when the fire was under control 　　　　to return to their homes.

　 A. the residents would be permitted　　　　　 B. had the residents been permitted

　 C. would the residents be permitted　　　　 D. the residents had been permitted

31. Something has to be done to stop our rivers from being polluted, 　　　　　　?

　 A. doesn’t it　　　 B. hasn’t it　　　　 C. does it　　　　 D. haven’t they

30. Water will continue to be 　　　　　　　it is today – next in importance to oxygen.

　 A. how　　　　　 B. which　　　　 C. as　　　　 D. what